JPH0243554Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention is designed to remove moisture and other foreign substances remaining in the die-casting mold used for casting precision molded products. The present invention relates to a cleaning device for cleaning a die-casting mold.

(Prior Art) Among automobile parts formed by casting, a control valve structure forming a hydraulic circuit of an automatic transmission has an extremely precise structure. For example, as shown in FIG. 4, such a control valve structure includes an upper body 40, a separate plate 42, and a lower body 44 as main parts, and these upper body 40 and lower body 44 are connected to an oil passage section 46 provided therein. A large number of dense partition walls are required to be formed with smooth casting surfaces.

As a casting method that allows molded products with such precise shapes to be obtained with high precision and is also highly productive, the cavity formed in the mold is filled with molten metal at high speed and high pressure. A die-casting method is known in which a molded product is obtained by solidifying it, and in casting by such a die-casting method, for example, as shown in Japanese Utility Model Application No. 54-152116,
Usually, the process includes a step of applying a mold release agent to the surface of the cavity forming part of the mold to promote mold release of the casting.

If the mold release agent used in such a case is applied to the surface of the cavity forming part of the mold in an overheated state, its constituent components will evaporate and the mold release agent will not adhere to the surface of the cavity forming part. It's no longer enough,
This results in the inability to achieve the desired goal. Therefore, in order to improve the adhesion of the mold release agent on the surface of the cavity forming part,
Cooling water is sprayed on the surface of the cavity forming part that is heated by pouring to maintain a moderate temperature (around 250℃).
After that, a release agent is applied. At this time, the cooling water sprayed on the surface of the cavity forming part is removed by blowing air, but conventionally, the cooling water is removed by air supply means that supplies air to the entire surface of the cavity forming part. Air is being blown out.

However, in a mold having a cavity forming part provided with a large number of complicated protrusions in order to obtain a molded product having a precise shape as described above, air is simply blown onto the surface of the cavity forming part. If this is done alone, the protruding portions will block the inflow of air and create areas where cooling water remains, such as near the lower ends of the plurality of protruding portions. If molten metal is injected into the cavity while there are areas with residual moisture in the cavity forming part, the residual moisture will evaporate and cause significant volumetric expansion, which will cause cavities in the molded product. This results in the inconvenience that this occurs.

In addition, when a core is used that is inserted into the cavity forming part of the mold during pouring in order to provide a part with a predetermined shape such as a perforated projection in the molded product,
Thin burrs are formed due to the solidification of the molten metal that has entered the minute gap between the core and the protruding part provided in the cavity forming part that receives it. In the case of spraying, such thin burrs tend to remain, and as a result, there is a possibility that movement and position regulation of the core in the cavity forming portion may not be performed properly.

(Purpose of the invention) In view of the above, the present invention is capable of cleaning the cavity forming part by sufficiently removing foreign matter such as moisture and thin burrs adhering to the cavity forming part of a die-casting mold. It is an object of the present invention to provide a cleaning device for a die casting mold that can remove such foreign substances extremely efficiently with a relatively simple configuration.

(Structure of the invention) The die-casting mold cleaning device according to the invention includes:
A guide hole is formed on the outside of the cavity forming part of the die-casting mold and guides the core into a through hole drilled in a protruding part provided in the cavity forming part, and a wall part forming the guide hole. The cavity is formed by blowing air through the communication path from the guide hole to the cavity forming part through the through hole bored in the protruding part. and an air passage for cleaning the area.

With this configuration, foreign substances such as moisture and thin burrs adhering to the cavity forming portion of the die-casting mold and the guide hole are blown out along the wall surface forming the inside of the guide hole through the communication path. The air that forms a swirling flow within the guide hole allows for efficient removal.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows an example of a die-cast mold cleaning device according to the present invention together with a part of a die-cast mold to which the device is applied. In FIG. 1, a fixed mold 10 forming a die-casting mold is used for casting precision molded products such as an upper body that constitutes a control valve structure used in the above-mentioned automatic transmission of an automobile. is,
It has a cavity forming portion 12 provided with a large number of protrusions 12a corresponding to the shape of the molded product. A plurality of protrusions 1 arranged in a predetermined position within the cavity forming portion 12
2a has through holes 14 bored therethrough, into which the core is inserted, and at positions facing each of the through holes 14 in the fixed mold 10, A plurality of guide holes 18 are provided to guide the core inserted into each through hole 14.

Each of the guide holes 18 has - in FIG.
As shown in Figure 2, which represents a cross section along the line,
A core 1 having a predetermined draft angle for forming a valve spool hole of a molded product (upper body)
6 is connected to an external hydraulic cylinder (not shown) and arranged so as to be freely inserted, and the guide hole 18 allows the core 16 to be inserted into the through hole 14 bored in the protruding part 12a of the cavity forming part 12. I will guide you as much as possible.

Furthermore, as shown in FIG. 1 and FIG. 2, inside the fixed mold 10, there is a section extending substantially perpendicularly to each guide hole 18 at a predetermined position below the guide hole 18, and extends from the end surface of the fixed mold 10. opening 20a in the
An air passage 20 having a diameter is provided. A communication passage 22 is provided at a position where the air passage 20 and each guide hole 18 intersect, allowing the air passage 20 and each guide hole 18 to communicate with each other. In other words, the air passage 20 opens through the communication passage 22 into the inner wall surface forming the guide hole 18 . This communication path 22 is - in FIG.
As shown in FIG. 3, which shows a cross section along the line, the guide hole 18 is
The hole is bored at a predetermined angle of inclination in a direction tangential to the inner wall surface forming the hole. Here, an example of the die-cast mold cleaning device according to the present invention includes the above-mentioned guide hole 18,
Air passage 20 and communication passage 2 having an opening 20a
It is composed of 2.

When casting is performed under such a configuration, the core 16 is inserted through the guide hole 18 of the fixed mold 10, and the protrusion of the cavity forming portion 12 is inserted as shown by the dashed line in FIG. Mold part 12a
After a movable mold (not shown) is fastened to the fixed mold 10 with the core 16 fitted into the through hole 14 drilled in the mold, a molten metal is formed by the cavity forming portion 12. It will be injected into the cavity and solidified, but before such operations are performed, the cavity forming portion 12 of the fixed mold 10 is cooled, cleaned, and coated with a mold release agent. Cooling of the cavity forming part 12 is performed by taking out the molded product obtained by the previous casting from the cavity forming part 12, and then spraying cooling water over the entire surface of the cavity forming part 12. Cleaning is then performed to remove the sprayed cooling water along with other foreign substances by air blown onto the cavity forming part 12, and then a mold release agent is applied to the surface of the cavity forming part 12.

In such a series of die casting processes, the cavity forming portion 1 of the fixed mold 10 is cleaned by the above-mentioned example of the die casting mold cleaning device according to the present invention.
Cleaning for No. 2 is performed as described below.

First, the air passage 2 arranged in the fixed mold 10
0, air is supplied from the opening 20a formed in the end surface of the fixed mold 10 by an air supply means (not shown). The air sent into the air passage 20 advances as shown by arrow F in FIG. 1 and reaches a position where it intersects with the guide hole 18. At this time, since the core 16 is removed from the guide hole 18, air is guided into the guide hole 18 from the air passage 20 through the communication passage 22. At this time, as described above, the communication passages 22 are opened in the tangential direction to the inner wall surface portions forming the guide holes 18, so that the air guided into the guide holes 18 Arrow R in FIG. 3 along the inner wall surface forming the
A swirling flow is formed as shown in . The air forming the swirling flow R is guided through the guide hole 18 and blown toward the cavity forming portion 12 of the fixed mold 10, and is then blown onto the protruding mold portion 12a provided in the cavity forming portion 12. , is sprayed onto each part of the cavity forming part 12 through the through hole 14 formed in the protruding part 12a. The air is blown from the guide hole 18 and passes through the cavity forming portion 1 through the through hole 14 bored in the protruding portion 12a.
The air blown onto the cavity 2 sufficiently reaches the spaces between the adjacent cavity forming parts 12, and as a result, the moisture adhering to the cavity forming part 12 is reduced to the moisture remaining near the lower end of each protruding part 12a. When the core 16 is sufficiently removed and the core 16 is fitted into the through hole 14 of the protrusion mold part 12a, a minute gap is created between the core 16 and the inner surface of the protrusion mold part 12a that forms the through hole 14. The molten metal that has flowed into the hole 14 is formed by solidification, and foreign matter such as thin burrs attached around the through hole 14 is also sufficiently removed.

In this way, in the cavity forming portion 12,
The air blown out from the guide hole 18
By spraying through the through hole 14 formed in the cavity forming portion 12, the spray is applied to the vicinity of the lower end of the protruding part 12a having a complicated shape provided in the cavity forming part 12, or to the protruding part 12a.
To sufficiently remove foreign matter remaining in areas where it is difficult to remove foreign matter by simply blowing air over the entire surface of the cavity forming portion 12, such as around the through hole 14 formed in the cavity. Therefore, the cavity forming portion 12 can be effectively cleaned in a short period of time. Moreover, the air is blown onto the cavity forming portion 12 by making the air passage 20 communicate with the guide hole 18 originally provided in the fixed mold 10 and supplying air into the air passage 20. This is done without the need for special air supply means.

Further, a part of the air blown into the guide hole 18 is also released while swirling toward the core 16, and the surface of the core 16 is also cleaned at the same time.

(Effect of the invention) As is clear from the above explanation, according to the die-casting mold cleaning device according to the present invention, the cavity-forming part of the die-casting mold has a large number of complex shapes. Even in the case of a dense piece with protrusions, the areas near the lower ends of the protrusions, between adjacent protrusions, and around the through holes drilled in the protrusions, etc. It is possible to blow enough air from the air passage through the communication path into the guide hole to form a swirling flow within the guide hole, without requiring any special air supply means. Foreign matter such as moisture and thin burrs adhering to various parts of the cavity forming part can be efficiently removed. Therefore, the cavity forming portion of the die-casting mold can be cleaned extremely effectively with a simple configuration.

[Brief explanation of the drawing]

FIG. 1 is a partial plan view showing an example of the die-casting mold cleaning device according to the present invention together with a part of the die-casting mold to which it is applied, FIG. 2 is a cross-sectional view taken along the - line in FIG. 1, and FIG. 3 2 is a sectional view taken along the - line in FIG. 2, and FIG. 4 is a schematic perspective view showing an example of a molded product having a dense shape cast by a die casting method. In the figure, 10 is a fixed mold, 12 is a cavity forming part, 16 is a core, 18 is a guide hole, 20 is an air passage, and 22 is a communication passage.

Claims (1)

[Claims for Utility Model Registration] A guide hole formed on the outside of a cavity forming part of a die-casting mold, for guiding a core into a through hole drilled in a protruding part provided in the cavity forming part; The wall portion forming the guide hole includes a communicating path that opens in a tangential direction to the wall portion, and the air through the communicating path is transferred from the guide hole to the transparent hole bored in the protruding portion. A cleaning device for a die-casting mold, comprising: an air passageway for cleaning the cavity-forming portion by spraying air onto the cavity-forming portion through the hole.